1. Field
Embodiments relate to a secondary battery module.
2. Description of the Related Art
A typical secondary battery module may include a plurality of unit batteries connected in series. The unit batteries may be secondary batteries. Each of the unit batteries may include an electrode assembly, a case having a space therein, a cap assembly coupled to the case to seal the case, and positive and negative terminals protruding through the cap assembly and electrically connected to positive and negative electrode collectors in the electrode assembly, respectively. The electrode assembly may include a separator interposed between a positive electrode and a negative electrode. The electrode assembly may be accommodated in the space of the case.
The positive and negative terminals of adjacent unit batteries may be connected to each other with, e.g., bus bars to achieve high capacity of the battery module. In the typical secondary battery module, the conductive bus bars may be fitted on male threaded positive and negative terminals of the adjacent unit batteries. Nuts may be screwed onto the positive and negative terminals to fix the bus bars to the positive and negative terminals. Due to this construction, the unit batteries are connected in series with each other.